ultimately to drop into the water. It may originally have been a mile from the river in the centre of an old plantation, but the mighty current sweeping around and into the bend has worn away the land, often dissolving it by acres, and as it dropped in, has piled the sediment on the opposite point, thus steadily moving the river over without materially changing the width, until it is ready to engulf the house. While the great river above the Ohio is generally bordered by limestone bluffs, making stable conditions, yet below, the Mississippi flows through a region wholly formed by its own deposits. It is said the alluvial basin below Cairo was once an estuary of the Gulf of Mexico, and that it has been raised in level, along with the entire southern portion of the Continent, about a hundred feet, and then filled in with the sediment the river carries down. This alluvial region is sometimes as much as seventy miles wide; and when not confined to the channel by levees, the natural course of a great Mississippi flood is to spread entirely over the basin. These floods will rise fifty feet, and the basin then becomes a great reservoir and storage-ground for the surplus waters, though the levee system has much restricted this. It is estimated that the annual discharge of the Mississippi is twenty-one million millions of cubic feet of water, and that it carries in a year four hundred millions of tons of solid material down to the Gulf to be deposited; thus cutting away from its banks a space equalling ten square miles of territory eighty feet deep. It takes one-fourth the rainfall of its valley down to the Gulf, or water equalling a depth of seven or eight inches over its whole drainage area, and the solid matter annually carried along and deposited there is equal to a body a mile square and three hundred and sixty feet high. The flow of the river is from one to six miles an hour in different stages and sections. The flood periods are in April and June, the river being above the mid-stage usually from January to August; and the lowest stage comes generally in October. MEMPHIS TO VICKSBURG.